Bipolar disorder is a dynamic illness with constantly changing symptom and syndrome presentations that[unreadable] confound interpretation of neuroimaging findings, as well as treatment response. This feature of the illness[unreadable] raises the need to examine patients as the condition evolves over time in order to clarify interactions[unreadable] between neuroimaging measures, clinical response and affective state. Careful longitudinal assessments[unreadable] and subject retention are critical elements to the success of the BITREC and its proposed projects. The[unreadable] Longitudinal Assessment Core (LAC) will serve this need and is a direct extension of over a decade of[unreadable] experience following young bipolar patients. Specifically, our experience with longitudinal studies is[unreadable] demonstrated by the success of a number of large, long-term projects. Our previous and ongoing projects[unreadable] provide an infrastructure for the longitudinal study of bipolar disorder from which the LAC will be developed.[unreadable] The LAC will be fully integrated with the other BITREC cores and projects as described in the Operational[unreadable] Plan. Dr. Paul Keck, Professor of Psychiatry and Pharmacology and Vice-Chair for Research in the[unreadable] Department of Psychiatry will direct the LAC. He will be responsible for overall core function and for[unreadable] overseeing infrastructure development. He will be assisted by several clinicians and staff to provide excellent[unreadable] clinical care and ongoing assessments to subjects enrolled in the BITREC. The LAC will hold staff meetings[unreadable] every other week to ensure that recruitment benchmarks are being met and to review subjects who have[unreadable] developed new affective episodes or symptoms in order to determine whether they qualify for additional[unreadable] BITREC projects. Standard operating procedures will be developed to maximize efficiency and meet[unreadable] objectives and benchmarks. Most decisions involving daily core function will be made by the personnel of the[unreadable] core under the direction of Dr. Keck. These decisions will be guided by and reported to the BITREC Steering[unreadable] Committee. Additionally, Dr. Keck will be integrated within the overall administrative structure of the BITREC[unreadable] by serving on the Steering Committee. With this structure established the LAC will be able to meet its[unreadable] primary functions which are: 1) to provide treatment to subjects actively participating in BITREC projects;[unreadable] 2) to provide ongoing clinical evaluations and excellent clinical care to subjects enrolled in the BITREC[unreadable] between projects; and 3) to identify subjects who meet criteria for a new BITREC project. By following and[unreadable] managing subjects across project, the LAC helps to further integrate the various components of the BITREC,[unreadable] assuring a cohesive and effective research center.